You have manage to pen a piece here that induces feelings of being out of control. Being stressed, or anxious is something that many people say they understand but they don't really, do they? They may feel nervous as they take an exam, or go for an interview, but this pales into insignificance compared with acute variations, such as you aptly describe. I can only imagine the sensation of not being able to swallow or breathe. It must feel like being strangled from an unseen force. Just experiencing this once would be enough to make the anxiety rise like boiling bile every time you encounter the same triggers. At first the symptoms would be small, but over time they would grow and simultaneously your world shrinks to one room. A terrifying thought and one I can only empathise with.